Foundation Academy

Lesson 3

R-Multiple Math

The single most important metric in trading — and why win rate alone is a trap.

Why Win Rate Lies

Trader A wins 70% of trades. Trader B wins 40%. Who makes more money?

Most people say Trader A. They're wrong. The answer depends on how big the wins are vs. the losses. A 70% win rate with $100 wins and $300 losses is a losing strategy. A 40% win rate with $400 wins and $100 losses is a printing-money strategy.

Win rate alone tells you nothing. The metric that matters is R.

What R Is

R = the dollars you risk on a trade. Calculate: (Entry − Stop) × Shares = 1R.

Every outcome gets measured in multiples of R. Stop hit = -1R. Target hit = +2R or +3R depending on how far the target was. Half-target = +1R.

Worked Example

Buy at $400, stop at $385, 10 shares.
1R = ($400 − $385) × 10 = $150
Stops out: -$150 = -1R
Sells at $445: +$450 = +3R
Sells at $415: +$150 = +1R

Check For Understanding

Quick Quiz

Answer 3+ correctly to mark this lesson complete.

1. Buy 50 shares of XYZ at $20, stop at $18. What is 1R?

2. Trader A: 70% win rate. Trader B: 40% win rate. Who makes more?

3. Three open positions, each risking 1R = $150. Account = $7,500. What's your portfolio heat?

4. Avg win = +2.5R. Avg loss = -1R. Win rate = 50%. What's expectancy?